Category: Member Spotlight

Karragullen horticulturist Chris Oliver is an expert when it comes to reviving old, diseased or damaged fruit trees.

“My philosophy is if you can keep a tree healthy, then you are strengthening it to be able to resist pest and disease attack,” he said. “The healthier the tree, the more environmental resistance it has. It’s virtually like our bodies, if we become weak and tired we are prone to all sorts of problems.”

Plying his trade in the Perth Hills under the banner Wilburnia Fruit and Flowers, Chris said every case of fruit tree regeneration was unique. “You have to size up the ecosystem first, and every tree presents a new challenge. You need to know the history of the tree before you can develop a plan,” he said.

“Each stage that you go through, from pruning deadwood to fertilising and watering, needs to be monitored carefully so that you can see the response.”

When developing a rejuvenation plan, Chris draws on knowledge gained personally as a grower and from his long career at TAFE as a horticultural lecturer. He keeps abreast of new technologies and believes in a combined organic and inorganic approach when it comes to growing fruit trees.

“It’s a thrill to see how trees respond and having the knowledge that you can do the job. I miss communicating that to students,” he said. Each regeneration project starts with a site analysis. Chris takes into account the health of the tree and its surrounds, as well as soil health, environmental conditions and water supply. Work then begins on bringing the tree back to good health using a step-by-step approach. “When trees are under stress, things go wrong and they get pests and diseases far easier,” he said.

Speaking from experience, Chris has been regenerating two Bedford cherry trees in his orchard, which is home to a range of stone fruit varieties, pomme fruit, citrus and four varieties of nuts.

It’s a thrill to see how trees respond and having the knowledge that you can do the job. I miss communicating that to students…

Chris said canker (Pseudomonas syringae), a bacterial airborne disease that causes limb dieback, had set into the cherry trees several years ago after a severe water shortage. “They are an old variety of cherry. They used to produce about 22kg of fruit a year, which was quite a big yield,” he said.

While several of the cherry trees have already died, Chris still has hope for the remaining two trees.

Site analysis

When he established his orchard almost 30 years ago, Chris faced the challenges of laterite outcrops, nutritionally deficient soil and a diminishing water supply.

“When I set my orchard up, I meant it to be a demonstration of what can grow in this area,” he said.

“We had to windrow the soil, because the laterite outcrops are close to the surface and minimise soil depth for growing fruit trees. “The gravelly soil is also poor on organic matter. For years I have been building up the soil mainly using composted brewery sludge, together with animal manures. It’s fantastic as a mulch and it’s marvellous at holding nutrients.”

Remnants of the natural fertiliser are scattered around the bases of the fruit trees in Chris’ orchard, but it has been difficult to source of late. “I used to get it from the old Swan Brewery. When it came off the truck it was a solid mass of half-set jelly, and you had to spread it out to dry until it is granular in form. My water use reduced from every day to twice a week after using the sludge.”

Water is a major problem in the area. Chris uses bore water on the property but said supply was very intermittent and he has to buy in water over summer.

“It’s just one of the things with change of climate that you have to deal with,” he said. Back to life

With canker rapidly spreading from branch to branch in his Bedford cherries, Chris said it was important to remove signs of the disease by pruning away the deadwood.

Member Spotlight – Chris Oliver FAIH

“It’s the initial stage of getting them back to new life,” he said. “If they are weak, the main thing is to not depend on cutting it back to a growing bud, which you normally do in pruning, but to cut it back to a living shoot. I generally do that prior to winter so I can see where the deadwood is.”

Now that winter has arrived, Chris said his next task would be to selectively and lightly prune the trees; the amount of material to remove depends on the type of fruit and the condition of the tree.

“You have to be very careful as to how much you prune back. The main reason is you want as much leaf area as possible for photosynthesis, which will help to build up the root system.”

Chris said he would apply a rapid release, NPK, plus trace elements fertiliser in spring, just before bud burst to give the trees a boost.

“The main thing is you have to be astute in where you apply the fertiliser. It has to be around the drip line, which should be 300mm to 400mm from the base of the trunk,” he said.

“I aim to get the nutrients taken up as quickly as possible in that burst of new growth, and then as the rains diminish I put on a light mulch.”

You have to be very careful as to how much you prune back. The main reason is you want as much leaf area as possible for photosynthesis, which will help to build up the root system…

Chris uses leafy tree clippings for mulch, applied about 300mm from the base of the trunk to about 300mm outside the drip line. He builds the mulch up to a thickness of about 80mm. He spreads cow manure under the mulch, which helps to hold in the nutrients.

At the end of summer, Chris applies a balanced fertiliser such as NPK Red.

It is also important to manage the pH of the soil, so Chris uses a testing kit to take random soil samples from around the tree to work out an average pH reading.

“I monitor the soil once a month,” he said. “Too alkaline and I will need to balance the soil with an acidifier like ammonium sulphate. If it’s too acidic, I add limestone calcium carbonate.”

While there is no quick fix for diseases such as canker, Chris believes he has found the formula for regeneration success. With perseverance and careful monitoring, he hopes to change the fate of not only his Bedford cherries but countless other fruit trees in the Perth Hills.

Andrew Prowse, an Australian Institute of Horticulture Registered Horticulturalist and the institute’s Vice- President has been appointed this year as an Adjunct Associate Professor in the School of Engineering and Science at James Cook University. The university has it main campus at Townsville with satellite campuses in Cairns and Singapore. Andrew has been involved with teaching at the university’s Centre for Tropical Urban & Regional Planning since 1994.

Andrew has extensive Landscape Architectural experience in both the private and government sector. A graduate in Landscape Architecture from the University of Canberra, after graduation he worked for The Council of the City of Sydney and Botany Municipal Council and responsible for a number of urban renewal and upgrading projects in Sydney including the Sir Joseph Banks Pleasure Gardens. Some may remember The Sir Joseph Banks Pleasure Gardens from the bus tour after the AIH’s 2014 Congress in Sydney – the park was a Bicentennial project recreation of the famed gardens beside Botany Bay which also featured Australia’s first zoo.

Since 1990 he has been practicing in tropical north Queensland, undertaking Main Street Programs, townscape improvements, resorts, housing, and garden projects in Queensland, Papua New Guinea, Thailand and China.

Since 1990 he has been practicing in tropical north Queensland, undertaking Main Street Programs, townscape improvements, resorts, housing, and garden projects in Queensland, Papua New Guinea, Thailand and China. Central to these projects has been the use of tropical design responses in creating functional and aesthetic solutions. Andrew collaborated with fellow AIH Registered Horticulturist and former AIH President Kim Morris in designing of one of China’s largest botanic themed parks, the 37 hectare Sino-Australian Friendship Garden on the Zhanjiang foreshore in southern China.

His work on the Paiam town project that involved the development of a new township in the remote Highlands of Papua New Guinea received listing by the United Nation’s Habitat Organisation as an Example of World’s Best Practice and received the Australian Institute of Landscape Architect’s Queensland Award for Excellence in Planning. He, along with Kim Morris, has also been retained by the Australian Office of War Graves for advice on the management, design and maintenance of Australia’s War Cemeteries in Queensland, the Northern Territory and P.N.G.

One of the projects that Andrew considers one his most interesting and challenging was working with AIH Registered Horticulturist Don Burke on a school campus in far north Queensland. After Category 5 Tropical Cyclone Larry devastated Innisfail town, severely damaging the State School, Landcare Australia and television garden program Backyard Blitz decided to provide a new playground. Andrew’s challenge was designing a prototype Environmental Study Garden in a 4 weeks construction, documentation and approval period. The design of a 150m2 wetland with jetty, 80m of rainforest boardwalk, stage and amphitheatre, aquaculture and butterfly house, centred around a new fully equipped study lab, was designed to be built largely by volunteers in 4 televised days. It was Backyard Blitz largest build on the programme. The project received a commendation award in the International Torsanlorenzo Prize, a world-wide prize for horticultural and landscape projects given by one of Europe’s largest nurseries.

Matt is a member of the Australian Institute of Horticulture and is an accredited Registered Horticulturist (RH 0026).

Tell us about your garden, Matt.

The garden, which is 3000sq.m., was built three years ago on a prominent derelict commercial site in Cairns and is part of the 202020 vision project that supports greening of our cities.

Locals have loved the transformation. It’s one of the largest collections of mature cycads, pachy­podiums, yuccas, ponytails and succulents, and it creates a modern-day representation of a prehistoric cycad forest.

Some specimens are hundreds of years old, such as Macrozamia mooreii, which is native to Carnarvon Gorge. The soil is typical Cairns deep sand, ideal for these plants. The garden is a pilot for a larger, nature-based theme park.

I’ve always been in love with the Jurassic age, not really for the dinosaurs but the habitat they lived in…

What makes your beautiful garden so special?

Many are rescue plants that I’ve collected over the past few years. I’m a landscaper and I’d see them unloved and unwanted at the tip.

Now people who know the site contact me, asking if I want special plants they are removing. Many need a crane or digger but I just can’t say no because I don’t want them to die.

Some are spectacular — they are just what I’ve been waiting for. There’s a lot of mature, rare stuff around because there were many specialist nurseries in the area in the 1970s.

Why do you love these particular plants, Matt?

I’ve always been in love with the Jurassic age, not really for the dinosaurs but the habitat they lived in.

I came to Cairns from England 12 years ago and every garden I went into was like a lolly shop for me, full of spectacular plants.

PHOTO: The spiked and armoured plants on display in the Jurassica Project’s garden are a hit with children. (ABC Far North: Adam Stephen)

What have been the biggest challenges for you, Matt?

Bringing in more than 500cu m of fill and the same of boulders to form hills and ridges from the flat, weed-infested site.

What’s next on the plans for you?

We have just bought a 20ha cane farm in a prominent highway position on the northside of Cairns.

We will add another bow and become sugar cane farmers while we develop this as the new Jurassica Theme Park site.

We hope to attract investors for the proposed theme park showcasing natural ecosystems of animals, plants and their habitats. Dedicated to conservation, education and entertainment, it aims to engage children and adults with real­istic displays such as primordial swamps, arid desert, lagoons, volcano and a cycad valley.

Our team has designed the whole project and developed a detailed business package for investors.

It all started at Wall’s Nursery, Richard (Dick) Wall and team, in Keysborough Victoria. It was here my love of Horticulture began with a 4-year Apprenticeship. This was an amazing workplace and I am very grateful for the comprehensive support and opportunities that were provided to me.

From there I moved to Alice Springs to a brief role at the Arid Zone Research Institute before starting at the Yulara tourist resort near Uluru as the Landscape Environmental Supervisor.

After three years. I was looking for another challenge so I moved to Brisbane to qualify as a TAFE teacher to begin my role in that space.

After moving to Esperance in Western Australia to establish a native plant nursery, I completed further studies in land management so I was able to coordinate a number of projects in catchment restoration, farm planning and forest science.

Moving north to the Kimberley, I worked with Aboriginal Ranger Groups and in community garden projects, teaching horticulture and land management units.

A shift to Darwin saw me focus on training in conservation and land management in both national parks and remote communities throughout the Top End.

After shifting to Tasmania in 2013. I continued to work in both the Kimberley and the Pilbara with Aboriginal ranger groups as a FIFO trainer. During this time, I also co-developed training resources for a number of CLM units for a Greening Australia/BHP funded project.

I have been very fortunate that I have had many opportunities to be involved in both horticulture and land management now for many years and in many diverse situations and states.

On the completion of this project I commenced work with TasTAFE and Conservation Volunteers Australia. Since the beginning of 2017 I have been full time with TasTAFE, and we plan on being here a while. We have a lovely home and sufficient land to manage a range of productive trees, grow vegetables and a wide range of natives to keep the birds interested.

I have been very fortunate that I have had many opportunities to be involved in both horticulture and land management now for many years and in many diverse situations and states. This of course has meant there is always lots to learn and study has been my constant “companion” for both interest and necessity with many nights, weekends and blocks given up to this. But has the journey to date been worthwhile? Absolutely and without a doubt.

In taking on the role of Vice President of the AIH, I am hoping to play an active role in both national and state activities. I have developed friendships with a number exceptionally committed Horticultural colleagues. I shall certainly be using those individuals to promote and engage with the industry here in Tasmania.

I am really keen to hear from anyone in the industry to chat about all things horticulture and any ideas you may have for AIH activities in Tasmania.